JP5252990B2 - Alkaline battery - Google Patents

Description

  The present invention relates to an alkaline battery excellent in leakage resistance, and more particularly to an alkaline battery in which a separator that closes a hole of a separator is improved in order to improve leakage resistance.

  Conventionally, when manufacturing a cylindrical alkaline battery having a relatively large size, such as single type 1 (LR20) or single type 2 (LR14), first, a positive electrode composite formed into a hollow cylindrical shape in a bottomed cylindrical positive electrode can. Store the agent. And the hot melt resin (hot melt type adhesive) was filled in the bottom part of the positive electrode can, and a cylindrical separator was inserted into the hollow part of the positive electrode mixture. At this time, the hot melt resin is cooled and cured, whereby the separator and the positive electrode can are bonded, and the bottom opening of the separator is closed. Then, after injecting electrolyte solution into a separator hollow part and making a separator and a positive electrode mixture impregnate electrolyte solution, a gel-like negative electrode mixture is filled into a separator hollow part. And the cylindrical alkaline battery is completed by sealing the open end of the positive electrode can with a current collector assembled in a separate process.

In this cylindrical alkaline battery, the positive electrode mixture and the negative electrode mixture are separated and insulated by closing the bottom opening of the separator using a separator made of a cured product of hot melt resin. Further, even when vibration or drop impact is applied to the battery, the vibration or impact is absorbed by the hot melt resin separator, and the positive electrode mixture and the negative electrode mixture are reliably isolated. Thus, the alkaline battery which isolate | separated the positive mix and the negative mix by obstruct | occluding the bottom part opening of a separator using hot-melt resin is proposed (for example, refer patent documents 1-4). .
JP 05-135777 A Japanese Patent Laid-Open No. 10-40927 JP 2000-67878 A JP 2001-266905 A

  By the way, when the alkaline battery having the above structure is short-circuited by an external circuit, the battery generates heat and its temperature rises. In particular, when a plurality of alkaline batteries are connected in series and short-circuited, the amount of heat generated by the battery further increases, and the battery surface temperature reaches a maximum of 140 ° C. to 160 ° C. due to the heat generated at this time.

  In an alkaline battery in a short state, almost no gas is generated inside the battery. However, in the overdischarged state after the short circuit is released, gas is likely to be generated, and the battery internal pressure increases. As a result, there has been a problem that the safety valve of the sealing gasket operates and the battery leaks, and the function as the battery is impaired.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an alkaline battery that is less likely to generate internal gas even when short-circuited outside the battery and has excellent liquid leakage resistance.

  Means [1] to [5] for solving the above problems are listed below.

  [1] A positive electrode mixture and a gel-like negative electrode mixture are accommodated in a bottomed cylindrical positive electrode can via a separator, and the hole in the central portion of the bottom of the separator is closed with a separator, whereby the gel In the alkaline battery in which the negative electrode mixture and the bottom of the positive electrode can are isolated, the separator is melted and softened in the process of temperature rise due to heat generation caused by a short circuit outside the battery to release the blockage of the hole. An alkaline battery comprising a thermoplastic resin, and an internal short path that connects between the gelled negative electrode mixture and the bottom of the positive electrode can can be formed as the thermoplastic resin melts and softens.

  Therefore, according to the means 1, since the separator does not melt and soften and keeps the solid state in the normal state where there is no short circuit outside the battery, the hole portion remains blocked, and the bottom portion of the gel negative electrode mixture and the positive electrode can Is maintained in isolation. When a short circuit occurs outside the battery and the battery generates heat, the separator is melted and softened in the process of increasing the temperature to release the clogging of the pores, and gas is generated in the gelled negative electrode mixture to generate an internal pressure. Rises. Then, the gelled negative electrode mixture leaks through the hole at the bottom of the separator, and is electrically connected to the inner surface of the positive electrode can to form an internal short path connecting the positive electrode side and the negative electrode side. Therefore, the short state is maintained inside the battery even after the short circuit outside the battery is released. Therefore, generation | occurrence | production of the internal gas beyond it is suppressed and leak-proof property improves.

  [2] The alkaline battery according to means 1, wherein the separator is made of a thermoplastic resin having a melting point of 86 ° C. or higher and 106 ° C. or lower.

  Therefore, according to the means 2, an internal short path is formed in a timely manner when a short circuit occurs, and the generation of further internal gas is surely suppressed without causing a deterioration in normal performance when the short circuit is not short outside the battery. be able to. If the melting point is too high, if the temperature does not rise considerably due to heat generation, the separator will not melt and soften, and therefore the timing for releasing the blockage of the hole will be delayed, and the generation of internal gas may not be sufficiently suppressed. On the other hand, if the melting point is too low, the separator may melt and soften even when the temperature rises during normal times, and the reliability is lowered.

  [3] The separator has a melting point of 86 ° C. or higher and 106 ° C. or lower, closes the hole, and has no conductivity, and a melting point of 86 ° C. or higher and 106 ° C. or lower. And a second thermoplastic resin disposed so as to be interposed between the first thermoplastic resin and the bottom of the positive electrode can and provided with conductivity. The alkaline battery described in 1.

  Therefore, according to the means 3, the first thermoplastic resin and the second thermoplastic resin are not melted and softened in a normal state in which no short circuit occurs outside the battery, and both remain solid. For this reason, both do not mix with each other, the hole portion remains blocked, and the isolated state of the gelled negative electrode mixture and the bottom of the positive electrode can is maintained. Therefore, there is no normal performance degradation. On the other hand, when a short circuit occurs outside the battery and the battery generates heat, the first thermoplastic resin and the second thermoplastic resin are melted and softened in the process of increasing the temperature, and the blockage of the hole is released. Both are mixed and become conductive as a whole. Then, as a result of the increase in internal pressure due to gas generation, the gelled negative electrode mixture leaks through the hole at the bottom of the separator, and the gelled negative electrode mixture and the inner surface of the positive electrode can pass through the conductive separator. Are electrically connected. Therefore, even if the gelled negative electrode mixture does not necessarily reach the inner surface of the positive electrode can, an internal short path connecting the positive electrode side and the negative electrode side can be formed.

  [4] The means 3 characterized in that the first thermoplastic resin and the second thermoplastic resin are melted and softened and mixed in the process of increasing the temperature and become conductive as a whole. The alkaline battery described.

  Therefore, according to the means 4, it is possible to reliably form the internal short path by mixing the two types of thermoplastic resins.

  [5] The means 4 characterized in that the first thermoplastic resin and the second thermoplastic resin are of the same kind, and only the second thermoplastic resin contains a conductive substance. Alkaline battery.

  Therefore, according to the means 5, if the two types of thermoplastic resins are different, it is impossible or difficult to mix with each other. It can be mixed relatively easily and uniform conductivity can be obtained.

  As described above in detail, according to the first to fifth aspects of the present invention, it is possible to provide an alkaline battery that is less likely to generate internal gas even when short-circuited outside the battery and that has excellent leakage resistance.

  Hereinafter, an alkaline battery 11 according to an embodiment of the present invention will be described in detail with reference to FIGS.

  As shown in FIG. 1, the positive electrode can 21 constituting the cylindrical alkaline battery 11 of the present embodiment is a bottomed cylindrical battery metal part that also serves as a positive electrode current collector. It is formed by drawing press processing. The power generation element 30 (that is, the positive electrode mixture 31, the separator 41, and the gelled negative electrode mixture 51) can be loaded into the internal space of the positive electrode can 21. In the positive electrode can 21, a plurality of positive electrode mixtures 31 formed into a hollow cylindrical shape are vertically stacked and press-fitted concentrically. The positive electrode mixture 31 forming a part of the power generation element 30 is an annular (or tubular) molding mixture containing an oxidizing agent such as manganese dioxide or nickel oxyhydroxide. A bottomed cylindrical separator 41 is inserted inside the positive electrode mixture 31. The separator 41 and the positive electrode mixture 31 are infiltrated with an alkaline electrolyte. The hollow portion of the separator 41 is filled with a gelled negative electrode mixture 51 formed by mixing a zinc alloy powder, a gelling agent, an alkaline electrolyte, and the like. In the present embodiment, an aqueous potassium hydroxide solution is used as the alkaline electrolyte. In the present embodiment, zinc alloy powder containing several tens to several hundred ppm of indium, bismuth and aluminum is used. As the gelling agent, for example, carboxymethyl cellulose, polyacrylic acid and its salts, sodium alginate, etherified starch and the like are suitable.

  On the inner surface side of the opening 22 of the positive electrode can 21, a negative electrode current collector 60 formed by assembling a negative electrode terminal plate 61, a current collecting rod 71, and a sealing gasket 81 is disposed and crimped. As a result, the positive electrode can 21 is sealed in a liquid-tight manner.

  The sealing gasket 81 has a boss portion 82 at the center, and a current collecting rod 71 can be inserted into a boss hole 82 a having a circular cross section passing through the boss portion 82. The sealing gasket 81 is a synthetic resin member having a circular shape in plan view, and is an injection-molded part made of a polyamide resin such as nylon. In place of the polyamide resin, a polyolefin resin such as polypropylene may be used.

  The negative terminal plate 61 is made of a conductive metal plate. The negative terminal plate 61 includes a central flat plate portion having a flat terminal surface formed on the outer surface, and an annular recess formed integrally with the outer peripheral portion of the central flat plate portion.

  The current collecting rod 71 is a rod made of a conductive metal such as a tin-plated brass wire, and its tip 73 is inserted and disposed in the gelled negative electrode mixture 51. On the other hand, the base end portion 72 of the current collecting rod 71 is inserted into the boss hole 82a of the boss portion 82 and is fixed to the central portion on the inner surface side of the negative electrode terminal plate 61 by spot welding or the like.

  As shown in FIG. 1, there is a hole 42 in the center of the bottom of the separator 41 of the present embodiment, and the hole 42 is blocked by a separator 90 made of one kind of resin, The gelled negative electrode mixture 51 and the bottom 23 of the positive electrode can 21 are isolated. More specifically, here, as the resin constituting the separator 90, a thermoplastic resin (first thermoplastic resin 91) having a melting point of 86 ° C. or higher and 106 ° C. or lower and not imparted with conductivity is used. It is used.

  The first thermoplastic resin 91 is not particularly limited as long as it satisfies the above melting point, and for example, solid paraffin or olefin can be selected. The first thermoplastic resin 91 may fill the entire space formed between the bottom portion of the separator 41 and the bottom portion 23 of the positive electrode can 21, but the hole portion 42 may be completely blocked. For example, it may be sufficient to fill a part of the space.

  The reason why the first thermoplastic resin 91 having such a melting point is used is as follows. That is, the first thermoplastic resin 91 is not melted and softened and maintains a solid state in a normal state in which no short circuit occurs outside the battery, so that the hole 42 remains blocked, and the gelled negative electrode mixture 51 and the positive electrode can This is because the state of being isolated from the bottom 23 of 21 is maintained. On the other hand, when a short circuit occurs outside the battery and the battery generates heat, the first thermoplastic resin 91 is melted and softened in the process of increasing the temperature, and the blockage of the hole 42 is released. In this case, as a result of the increase in internal pressure due to gas generation in the gelled negative electrode mixture 51, the gelled negative electrode mixture 51 leaks through the hole 42 at the bottom of the separator 41, and the positive electrode can 21 An internal short path is formed which is electrically connected to the inner surface and connects the positive electrode side and the negative electrode side.

  In the alkaline battery 11A of the modification of the present embodiment shown in FIG. 2, the hole 42 at the center of the bottom of the separator 41 is closed with a separator 90A made of two kinds of resins, so that the gel-like negative electrode composite is obtained. The agent 51 and the bottom 23 of the positive electrode can 21 are isolated. More specifically, here, as one resin constituting the separator 90A, a thermoplastic resin (first thermoplastic resin 91) having a melting point of 86 ° C. or higher and 106 ° C. or lower and not imparted with conductivity. ) Is used. The first thermoplastic resin 91 is disposed in the hole 42 and substantially closes the hole 42. Further, as the other resin constituting the separating material 90A, a second thermoplastic resin 92 having a melting point of 86 ° C. or higher and 106 ° C. or lower and imparted with conductivity is used. The second thermoplastic resin 92 is disposed so as to be interposed between the first thermoplastic resin 91 and the bottom 23 of the positive electrode can 21.

  The reason why the first thermoplastic resin 91 and the second thermoplastic resin 92 having such melting points are used is as follows. That is, in the normal time when there is no short circuit outside the battery, the first thermoplastic resin 91 and the second thermoplastic resin 92 are not melted and softened and both remain solid. For this reason, both are not mixed with each other, and the hole 42 is also closed, and the gelled negative electrode mixture 51 and the bottom 23 of the positive electrode can 21 are maintained in an isolated state. On the other hand, when a short circuit occurs outside the battery and the battery generates heat, the first thermoplastic resin 91 and the second thermoplastic resin 92 are melted and softened in the process of increasing the temperature, and the blocking of the hole 42 is released. This is because the two are mixed and become conductive as a whole. In this case, as a result of the increase in internal pressure due to gas generation, the gelled negative electrode mixture 51 leaks through the hole 42 at the bottom of the separator 41, and the gelled negative electrode mixture passes through the conductive separator 90A. The agent 51 and the inner surface of the positive electrode can 21 are electrically connected. Therefore, even if the gelled negative electrode mixture 51 does not necessarily reach the inner surface of the positive electrode can 21, an internal short path connecting the positive electrode side and the negative electrode side is formed.

  The first thermoplastic resin 91 and the second thermoplastic resin 92 are not particularly limited as long as the above melting point conditions are satisfied, and for example, solid paraffin or olefin can be selected. The first thermoplastic resin 91 and the second thermoplastic resin 92 may be the same type or different types, but it is preferable to select the same type. That is, when different types of thermoplastic resins are used, the properties such as the melting point are usually different, so that it may be impossible or difficult to mix them together. In that respect, if the same kind of thermoplastic resin is used, the various properties including the melting point are approximated in the first place, so that they can be melted and softened almost simultaneously in the course of temperature rise and mixed relatively easily. Therefore, uniform conductivity can be obtained as a whole after melting.

  Here, a conductive material is uniformly dispersed in the second thermoplastic resin 92 in order to impart conductivity. The amount of the conductive material is not limited, but is preferably 1% by weight or more and 10% by weight or less, for example. This is because if it is less than 1% by weight, it is too small to provide sufficient conductivity. On the other hand, if it exceeds 10% by weight, the electrical conductivity becomes too high, and it becomes easy to short-circuit in normal times, and the cost increases as the proportion of the conductive material increases. As such a conductive substance, for example, it is preferable to add at least one selected from graphite, carbon black, and metal.

  The volumes of the first thermoplastic resin 91 and the second thermoplastic resin 92 are not particularly limited and are arbitrary, but in the case of FIG. 2, the volume of the second thermoplastic resin 92 is the first thermoplastic resin 91. It is larger than the volume. This is because if the volume ratio relationship is reversed, the resin as a whole may not be imparted with sufficient and uniform conductivity when melted and mixed. The first thermoplastic resin 91 has a diameter smaller than the inner diameter of the concave portion on the inner surface side of the positive electrode terminal 24 of the positive electrode can 21. On the other hand, the second thermoplastic resin 92 has a diameter larger than the inner diameter of the recess. The lower surface side of the first thermoplastic resin 91 is in contact with the second thermoplastic resin 92 and is completely surrounded by the second thermoplastic resin 92. As a result, the first thermoplastic resin 91 is configured not to directly contact the bottom surface of the positive electrode can 21.

  Next, a procedure for manufacturing the alkaline batteries 11 and 11A of the present embodiment will be described.

  In order to manufacture the alkaline battery 11 shown in FIG. 1, first, a positive electrode mixture 31 that has been previously formed into a hollow cylindrical shape is press-fitted into a bottomed cylindrical positive electrode can 21. Thereafter, a sealant (not shown) is applied to the inner peripheral surface of the opening 22 in the positive electrode can 21 as necessary. Next, the first thermoplastic resin 91 is supplied to the bottom 23 of the positive electrode can 21. In this case, the melted first thermoplastic resin 91 may be dropped into the positive electrode can 21, or the solid first thermoplastic resin 91 that is not melted is dropped into the positive electrode can 21. May be. Furthermore, the separator 41 is loaded into the hollow part of the positive electrode mixture 31, and the bottom part is pressed against the first thermoplastic resin 91 in a molten state, thereby closing the hole part 42 at the center part of the bottom part. Thereafter, the electrolytic solution is injected into the cylinder of the separator 41 so that the electrolytic solution is infiltrated into the separator 41 and the positive electrode mixture 31, and then the gel-like negative electrode mixture 51 is filled into the cylinder of the separator 41. Thereafter, the negative electrode current collector 60 including the negative electrode terminal plate 61, the current collector rod 71, and the sealing gasket 81 is disposed in the opening 22 of the positive electrode can 21. In this state, the opening 22 of the positive electrode can 21 is subjected to curling and drawing to seal it, thereby completing the alkaline battery 11.

  Moreover, there are the following four methods for manufacturing the alkaline battery 11A shown in FIG.

  Manufacturing method 1 (refer to manufacturing method A in FIG. 3): First, a positive electrode mixture 31 formed in a hollow cylindrical shape in advance is press-fitted into a bottomed cylindrical positive electrode can 21. Thereafter, a sealant (not shown) is applied to the inner peripheral surface of the opening 22 in the positive electrode can 21 as necessary. Next, the 2nd thermoplastic resin 92 which provided electroconductivity to the bottom part 23 of the positive electrode can 21 is supplied. In this case, the melted second thermoplastic resin 92 may be dropped into the positive electrode can 21, or the solid second thermoplastic resin 92 that is not melted is dropped into the positive electrode can 21. May be. Next, a small amount of the melted first thermoplastic resin 91 is supplied to the central portion of the upper surface of the solidified second thermoplastic resin 92. Then, the separator 41 is loaded into the hollow portion of the positive electrode mixture 31, and the bottom portion of the separator 41 is pressed against the melted first thermoplastic resin 91, thereby closing the hole portion 42 in the center portion of the bottom portion. Thereafter, the electrolytic solution is injected into the cylinder of the separator 41 so that the electrolytic solution is infiltrated into the separator 41 and the positive electrode mixture 31, and then the gel-like negative electrode mixture 51 is filled into the cylinder of the separator 41. Thereafter, the negative electrode current collector 60 including the negative electrode terminal plate 61, the current collector rod 71, and the sealing gasket 81 is disposed in the opening 22 of the positive electrode can 21. In this state, the opening 22 of the positive electrode can 21 is curled and drawn to seal it, thereby completing the alkaline battery 11A.

  Manufacturing method 2 (refer to manufacturing method B in FIG. 3): The positive electrode mixture 31 is press-fitted into the bottomed cylindrical positive electrode can 21 and coated with a sealing agent as necessary, and then the bottom 23 of the positive electrode can 21 is formed. A second thermoplastic resin 92 is supplied. Next, the separator 41 is loaded into the hollow portion of the positive electrode mixture 31, and the bottom of the separator 41 is pressed against the second thermoplastic resin 92 in a molten state. Next, a small amount of the first thermoplastic resin 91 is supplied to the center of the bottom of the separator 41 to close the hole 42. Then, electrolyte solution injection, gelled negative electrode mixture filling, placement of the negative electrode current collector 60, and sealing are sequentially performed to complete the alkaline battery 11A.

  Manufacturing method 3 (refer to manufacturing method C in FIG. 3): The positive electrode mixture 31 is press-fitted into the bottomed cylindrical positive electrode can 21 and a sealing agent is applied as required, and then the bottom 23 of the positive electrode can 21 is formed. A second thermoplastic resin 92 is supplied. Next, a separator 41 whose hole 42 is closed with the first thermoplastic resin 91 is prepared in advance, and this closed separator 41 is loaded into the hollow portion of the positive electrode mixture 31. Then, electrolyte solution injection, gelled negative electrode mixture filling, arrangement of the negative electrode current collector 60, and sealing are sequentially performed to complete the alkaline battery 11A.

  Production method 4 (see production method D in FIG. 3): The positive electrode mixture 31 is press-fitted into a bottomed cylindrical positive electrode can 21 and a sealant is applied as necessary. Next, a separator 41 is prepared in which the hole portion 42 is previously closed with the first thermoplastic resin 91 and the second thermoplastic resin 92 is provided so as to cover the bottom surface from the lower surface side. Then, the closed separator 41 is loaded into the hollow portion of the positive electrode mixture 31. Then, electrolyte solution injection, gelled negative electrode mixture filling, arrangement of the negative electrode current collector 60, and sealing are sequentially performed to complete the alkaline battery 11A.

  Hereinafter, examples in which the above-described embodiment and its modifications are more specific will be described.

A. Preparation of evaluation sample and evaluation test method

  Here, several alkaline batteries 11A (LR20) having the structure shown in FIG. 2 were produced and used as samples for evaluation. For the first thermoplastic resin 91, solid paraffin (“Wax Rex 2480” manufactured by ExxonMobil) or olefin (“Imelt A-50” manufactured by Daikyo Co., Ltd.) was used. Similarly, for the second thermoplastic resin 92, solid paraffin (“Wax Rex 2480” manufactured by ExxonMobil) or olefin (“Imelt A-50” manufactured by Daikyo Co., Ltd.) is used, and a small amount of conductive material is used as the conductive material. Graphite or copper powder was added and dispersed uniformly.

  And the following leak-proof tests were done using each produced alkaline battery 11A. That is, two alkaline batteries 11A were connected in series or four in series, were short-circuited for 1 hour in this state, and were allowed to stand for 10 days after the short-circuit was opened. The number of liquid leaks observed at this point was investigated (N = 20). The results are shown in Table 1.

B. Results of evaluation test

  As shown in Table 1, with respect to Examples 1 to 7 in which the melting points of two types of resins were set within the range of 86 ° C. or higher and 106 ° C. or lower, leakage occurred both in the direct connection and in the four serial connection No liquid was observed. Therefore, all of these were excellent in leakage resistance. Further, it was found that suitable results can be obtained when the content of the conductive material in the second thermoplastic resin 92 is in the range of 1% by weight to 10% by weight. Furthermore, also about Example 8 which changed the kind of electroconductive substance from the copper powder which is a kind of electroconductive metal from graphite, it turned out that a suitable result is obtained similarly to Examples 1-7.

On the other hand, in Comparative Examples 1 to 3 in which the melting point of the resin was higher than that in each Example, leakage was observed and the leakage resistance was poor. Further, in Comparative Example 4 where the melting point of the resin is lower than in each Example, no liquid leakage was observed, but the internal short path may be formed even in the normal operating temperature range, so the reliability is high. It was low and could not be said to be practically preferable.
C. Conclusion

  Therefore, according to the alkaline batteries 11 and 11A, when a short circuit occurs outside the battery and the battery generates heat, the clogging of the hole 42 is released by melting and softening of the separators 90 and 90A. An internal short path connecting the sides is formed. Therefore, the short state is maintained inside the battery even after the short circuit outside the battery is released. Therefore, generation | occurrence | production of the internal gas beyond it is suppressed and leak-proof property improves.

  In addition, you may change embodiment of this invention as follows.

  In each example of the above embodiment, the present invention is embodied in an LR20 (single type) cylindrical alkaline battery, but other types of cylindrical alkaline batteries, such as LR14 (single type), LR6 ( AA type), LR03 (single type 4), LR1 (single type 5) may be embodied.

  Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the embodiments described above are listed below.

  (1) In any one of the above means 3 to 5, the volume of the second thermoplastic resin is larger than the volume of the first thermoplastic resin.

  (2) In any one of the means 3 to 5 and the idea 1, the first thermoplastic resin has a diameter smaller than the inner diameter of the concave portion on the inner surface side of the positive electrode terminal of the positive electrode can. The second thermoplastic resin has a diameter larger than the inner diameter of the recess.

  (3) In any one of the means 3 to 5 and the thoughts 1 and 2, 1% by weight or more and 10% by weight or less of a conductive material is uniformly dispersed in the second thermoplastic resin.

  (4) In any one of the means 3 to 5 and the thoughts 1 and 2, the second thermoplastic resin contains at least one conductive material selected from graphite, carbon black, and metal. That.

  (5) The alkaline battery manufacturing method according to the above means 3, wherein the positive electrode mixture is loaded in a bottomed cylindrical positive electrode can, and then the second thermoplastic resin is placed on the bottom of the positive electrode can. And further supplying the first thermoplastic resin onto the second thermoplastic resin, and then filling the hollow portion of the positive electrode mixture with the separator to close the hole. A method for producing an alkaline battery.

  (6) The method for producing an alkaline battery according to the above means 3, wherein the positive electrode mixture is loaded in a bottomed cylindrical positive electrode can, and then the second thermoplastic resin is placed on the bottom of the positive electrode can. In addition, after the separator is loaded into the hollow portion of the positive electrode mixture, the first thermoplastic resin is supplied to the hole of the separator to close the hole. Manufacturing method.

  (7) The method for producing an alkaline battery according to the above means 3, wherein the positive electrode mixture is loaded in a bottomed cylindrical positive electrode can, and then the second thermoplastic resin is placed on the bottom of the positive electrode can. And supplying the separator whose pores have been previously closed with the first thermoplastic resin into the hollow portion of the positive electrode mixture.

  (8) The method for producing an alkaline battery according to the above means 3, wherein the positive electrode mixture is loaded into a bottomed cylindrical positive electrode can, and then the second thermoplastic resin is placed at the bottom of the positive electrode can. The separator having the hole previously closed with the first thermoplastic resin and the bottom covered with the second thermoplastic resin is loaded into the hollow portion of the positive electrode mixture. A method for producing an alkaline battery.

Sectional drawing which shows the alkaline battery of embodiment which actualized this invention. Sectional drawing which shows the alkaline battery of the modification of this embodiment. Schematic for demonstrating the manufacturing procedure of the alkaline battery of the modification of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11,11A ... Alkaline battery 21 ... Positive electrode can 31 ... Positive electrode mixture 41 ... Separator 42 ... Hole 51 ... Gel-like negative electrode mixture 90, 90A ... Separating material 91 ... 1st thermoplastic resin 92 ... 2nd thermoplasticity resin

Claims (5)

A positive electrode mixture and a gel-like negative electrode mixture are accommodated in a bottomed cylindrical positive electrode can via a separator, and the hole in the center of the bottom of the separator is closed with a separating material, thereby the gel-like negative electrode mixture. In the alkaline battery in which the agent and the bottom of the positive electrode can are isolated,
The separator is made of a thermoplastic resin that melts and softens in the process of temperature rise due to heat generation due to a short circuit outside the battery and releases the blockage of the hole,
An alkaline battery characterized in that an internal short path connecting between the gelled negative electrode mixture and the bottom of the positive electrode can can be formed as the thermoplastic resin melts and softens.   The alkaline battery according to claim 1, wherein the separator is made of a thermoplastic resin having a melting point of 86 ° C. or higher and 106 ° C. or lower.   The separator has a melting point of 86 ° C. or higher and 106 ° C. or lower, the first thermoplastic resin that closes the hole and has no conductivity, and a melting point of 86 ° C. or higher and 106 ° C. or lower, The first thermoplastic resin and a second thermoplastic resin disposed so as to be interposed between the first thermoplastic resin and the bottom of the positive electrode can and provided with conductivity. Alkaline battery.   The first thermoplastic resin and the second thermoplastic resin are melted and softened and mixed in the process of increasing the temperature, and become conductive as a whole. Alkaline battery.   5. The alkali according to claim 4, wherein the first thermoplastic resin and the second thermoplastic resin are of the same type, and only the second thermoplastic resin contains a conductive substance. battery.

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